A former WHO director says the coronavirus could 'burn out' before we have a vaccine

• Dr. Karol Sikora, a British oncologist and a former WHO director, tweeted that there's a "real chance" the novel coronavirus could "burn out" before a vaccine is developed.
• He suspects the world is more immune than estimates suggests.
• Other experts and research has been less optimistic, with some indicating less than 10% of the world has been exposed to the virus.
• Visit Business Insider's homepage for more stories.

A vaccine against the novel coronavirus is "the one great hope" of eliminating COVID-19, according to World Health Organization's Executive Director of Health Emergencies Mike Ryan.

Other scientists and researchers have emphasized that a widely-distributed vaccine is the only way vulnerable people like older adults and those with underlying conditions can be safe at large gatherings including workplaces, churches, and cruises.

A vaccine will also influence when schools and sporting events fully resume and borders can open.

But in a tweet, one expert said we may not need to wait until one is developed to overcome the current pandemic.

On May 16, Dr. Karol Sikora, a British oncologist who used to lead the WHO's cancer program, wrote "there's a real chance the virus will burn out naturally before any vacccine is developed."

He added that he suspects the population has more immunity than estimates suggest, and that it remains important to slow the spread of the virus.

Some estimates suggest less than 10% of the world has been exposed to the virus

Sikora's predictions are encouraging, but don't match what other experts and research suggests.

Some research suggests less than 10% of the world has been exposed to the coronavirus, meaning that without a widely-used vaccine, it could take four or five years to develop the type of "herd immunity" that could control the outbreak, Business Insider's Hilary Brueck reported.

"A safe, effective vaccine is the only way to safely build herd immunity to this virus now," Emily Toth Martin, an associate professor of epidemiology at the University of Michigan School of Public Health, told Business Insider.

"This is not just about getting through the current crisis," she added. "If this virus stays around, we need a vaccine to prevent resurgences in future generations."

During the World Health Assembly May 18, the current WHO director-general Tedros Adhanom Ghebreyesus, stressed conquering the coronavirus is still a long ways off.

"Early serology studies are painting a consistent picture: even in the worst-affected regions, the proportion of the population with the tell-tale antibodies is no more than 20%, and in most places, less than 10%," he said. "In other words: The majority of the world's population remains susceptible to this virus. The risk remains high and we have a long road to travel."